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Tuesday, 27 December 2011

The Moon: What We've Learned So Far

We all know the moon is not made of cheese, but what is it made of ?

Believe it or not, there's a lot of ice on it. Scientists have been able to
study samples brought back from the moon's surface during the Apollo missions.
In addition, recent missions like NASA's Lunar CRater Observation and Sensing
Satellite, or LCROSS, and Lunar
Reconnaissance Orbiter, or LRO, made it possible to study the moon's
composition in space. With LCROSS and LRO, NASA has been able to observe lunar
dust within the moon's craters and make a more detailed lunar topographical
study than ever before -- and they've made some pretty exciting discoveries
about the moon's composition.

The biggest finding, of course, was evidence of water on the moon, but that
was only the beginning of the discoveries. Along with water, LCROSS also
uncovered evidence that the moon has its own water cycle and that the water is
typically present in the form of pure ice crystals.

Scientists were able to study the moon's composition in 2009 when LCROSS
impacted in a deep crater on the moon's surface, ejecting a plume of material
that might not have seen sunlight in millions of years. Instruments on the
orbiting LRO satellite picked up traces of ice crystals and other volatiles,
compounds that freeze and are trapped in the cold lunar craters and vaporize
when warmed by the sun. As much as 20 percent of the material kicked up by the
LCROSS impact was made up of volatiles, including methane, ammonia, hydrogen
gas, carbon dioxide and carbon monoxide. The instruments also discovered
relatively large amounts of light metals such as sodium, mercury and possibly
even silver. Scientists believe the water and mix of volatiles that LCROSS and
LRO detected could be the remnants of a comet impact. According to scientists,
these volatile chemical by-products are also evidence of a cycle through which
water ice reacts with lunar soil grains.

The proportion of volatiles to water in the lunar soil indicates a process
called "cold grain chemistry" is taking place. Scientists have theorized that
this process takes thousands of years and could happen on other frigid bodies,
like asteroids and moons of other planets.

The moon is more than a giant rock circling Earth; it is a body with its own
chemistry and composition that NASA has only just begun to reveal. As NASA looks
toward the future for new lunar missions, its knowledge of the moon's
composition could help future explorers. The existence of mostly pure water ice
could mean future human explorers won't have to carry their own water source for
valuable life support resources. In addition, an abundant presence of hydrogen
gas, ammonia and methane could provide possible sources of fuel for future
surface activities. Who knows -- in a few decades, lunar astronauts may return
to Earth using the moon's own "lunar fuel."